Decoding apparatus, decoding method, and program

ABSTRACT

A tactile reproduction system is made more efficient by achieving a data amount reduction of a tactile signal while ensuring reproducibility of a tactile sense. 
     A decoding apparatus according to the present technology includes a decoding unit configured to decode tactile coded data obtained by performing encoding of compressing an information amount, on a tactile signal using higher-order perception in a tactile sense. Therefore, a data amount reduction of a tactile signal can be performed in accordance with a tactile characteristic of a human.

CROSS-REFERENCE TO RELATED APPLICATIONS

The present application claims the benefit under 35 U.S.C. § 120 as acontinuation application of U.S. application Ser. No. 17/254,792, filedon Dec. 21, 2020, which claims the benefit under 35 U.S.C. § 371 as aU.S. National Stage Entry of International Application No.PCT/JP2019/017709, filed in the Japanese Patent Office as a ReceivingOffice on Apr. 25, 2019, which claims priority to Japanese PatentApplication Number JP2018-122962, filed in the Japanese Patent Office onJun. 28, 2018, each of which applications is hereby incorporated byreference in its entirety.

TECHNICAL FIELD

The present technology relates to a decoding apparatus that decodes anencoded tactile signal, a method of the same, and a program.

BACKGROUND ART

In recent years, an application that applies tactile stimulation using atactile presentation device being in contact with the skin of a humanhas been used in various scenes. Here, the “tactile presentation” meansthe generation of tactile stimulation.

For example, in a touch panel-equipped mobile terminal such as asmartphone, by applying tactile stimulation to a finger by vibrating apanel (or casing) at the time of a touch operation of the panel, apseudo touch sense of a button is created.

In music listening, some apparatuses enhance deep bass sound byincorporating a tactile presentation device into a headphone casing, andapplying tactile stimulation in synchronization with music reproduction.

In the field of computer games and virtual reality (VR), someapparatuses enhance immersive feeling of a user by interactivelyapplying tactile stimulation in accordance with a scene by a tactilepresentation device installed in a controller in accordance with anoperation of the user.

In amusement facility, some apparatuses enhance realistic feeling ofvisitors by applying tactile stimulation using a tactile presentationdevice installed in a seat in a movie theater, an entertainment park, orthe like in accordance with a scene.

Furthermore, as for apparatuses in a research and development phase, inremotely controlling a robot and the like, some apparatuses help hazardanticipation by feeding back a vibration received by the robot or anoperated target object, to a controller held by an operator, and causingthe operator to intuitively detect a surrounding situation of the robotor the target object (e.g., disaster assistance robot<http://www.rm.is.tohoku.ac.jp/quince_mech/#_8>)

Moreover, in the medical field, the research has been conducted forenhancing the accuracy of surgery by feeding back feeling (stiffness)felt when forceps of an endoscope touch an organ at the time of anoperation of a surgical robot, to an operator (e.g., surgical supportrobot “da Vinci surgical system”<http://techon.nikkeibp.co.jp/article/FEATURE/20150217/404460/?P=2>)

Note that the related prior arts include Patent Document 1 describedbelow. Patent Document 1 discloses a technology of generating a tactilesignal on the basis of a voice signal, instead of generating a tactilesignal indicating a pattern of tactile stimulation by sensing tactileinformation such as vibration.

CITATION LIST Patent Document Patent Document 1: Japanese PatentApplication Laid-Open No. 2015-53038 SUMMARY OF THE INVENTION Problemsto be Solved by the Invention

Here, a tactile reproduction system that reproduces tactile informationis considered to include a plurality of tactile presentation devicesprepared for applying tactile stimulation to a plurality of regions of ahuman body, communicate a tactile signal in a wired or wireless manner,and perform other operations.

However, in accordance with an increase in the number of regions towhich tactile stimulation is applied, the number of channels of tactilesignals also increases, and an increase in a data amount is caused. If adata amount of a tactile signal increases, an increase in processingburden related to tactile reproduction, transmission delay, and the likemight be caused, which is undesirable.

The present technology has been devised in view of the above-describedcircumstances, and the object of the present technology is to make atactile reproduction system more efficient, by achieving a data amountreduction of a tactile signal while ensuring reproducibility of atactile sense.

Solutions to Problems

A decoding apparatus according to the present technology includes adecoding unit configured to decode tactile coded data obtained byperforming encoding of compressing an information amount, on a tactilesignal using higher-order perception in a tactile sense.

Therefore, a data amount reduction of a tactile signal can be performedin accordance with a tactile characteristic of a human.

In the above-described decoding apparatus according to the presenttechnology, it is desirable that the decoding unit decodes the tactilecoded data having been subjected to encoding of compressing aninformation amount using phantom sensation.

Therefore, in response to a case where similar tactile stimulation is tobe simultaneously applied to three or more regions of a human body, adata amount reduction can be performed in accordance with a tactilecharacteristic of a human.

In the above-described decoding apparatus according to the presenttechnology, it is desirable that the tactile coded data includes usagechannel designation information for designating a usage channel fromamong three or more channels of tactile signals, and the decoding unitoutputs a tactile signal of a channel indicated by the usage channeldesignation information.

Therefore, in implementing a data amount reduction that uses phantomsensation, the decoding apparatus needs not perform processing such asprocessing of determining whether or not phantom sensation is used, byanalyzing a tactile signal, and is only required to perform simpleprocessing of outputting a tactile signal in accordance with usagechannel designation information included in tactile coded data.

In the above-described decoding apparatus according to the presenttechnology, it is desirable that the decoding unit decodes the tactilecoded data having been subjected to encoding of compressing aninformation amount using an apparent movement.

Therefore, in response to a case where similar tactile stimulation is tobe sequentially applied to different regions of a human body, a dataamount reduction can be performed in accordance with a tactilecharacteristic of a human.

In the above-described decoding apparatus according to the presenttechnology, it is desirable that the tactile coded data includes usagepresence/absence information indicating usage presence/absence of anapparent movement, and the decoding unit decodes the tactile coded dataon the basis of the usage presence/absence information.

Therefore, in implementing a data amount reduction that uses an apparentmovement, the decoding apparatus needs not perform processing such asprocessing of determining whether or not an apparent movement is used,by analyzing a tactile signal, and is only required to perform simpleprocessing of outputting a tactile signal in accordance with usagepresence/absence information included in tactile coded data.

In the above-described decoding apparatus according to the presenttechnology, it is desirable that the tactile coded data includes atactile signal of only a single channel among usable channels beingchannels of tactile signals that can use an apparent movement, andoutput control information indicating an output channel and an outputtiming of the tactile signal, and the decoding unit outputs the tactilesignal of the single channel in accordance with the output controlinformation.

Therefore, in implementing tactile reproduction that uses an apparentmovement, tactile coded data needs not include a tactile signal of eachchannel to which tactile stimulation is to be applied, and it issufficient that a tactile signal of a single channel is included.

In the above-described decoding apparatus according to the presenttechnology, it is desirable that the single channel is a channel with anearliest signal rising timing among signals of the usable channels.

Therefore, in applying earliest tactile stimulation among sequentialtactile stimulation related to an apparent movement, it becomesunnecessary to stand by until a tactile signal indicating second orsubsequent tactile stimulation is acquired.

In the above-described decoding apparatus according to the presenttechnology, it is desirable that the decoding unit decodes the tactilecoded data in which a size of a block indicating a processing unit in atime direction is made variable.

Therefore, as for a tactile signal serving as a time signal, a specificwaveform portion and other portions can be treated as data includingdifferent blocks.

In the above-described decoding apparatus according to the presenttechnology, it is desirable that the tactile signal is a signal that isbased on a detection signal of a tactile sensor.

Therefore, tactile reproduction can be performed on the basis ofactually-sensed tactile information.

In the above-described decoding apparatus according to the presenttechnology, it is desirable that the tactile signal is a signal that isbased on a voice signal.

Therefore, tactile information having high association with voiceinformation can be reproduced.

Furthermore, a decoding method according to the present technology is adecoding method of decoding tactile coded data obtained by performingencoding of compressing an information amount, on a tactile signal usinghigher-order perception in a tactile sense.

Also by such a decoding method, effects similar to those of theabove-described decoding apparatus according to the present technologycan be obtained.

Moreover, a program according to the present technology is a program forcausing an information processing device to implement a function ofdecoding tactile coded data obtained by performing encoding ofcompressing an information amount, on a tactile signal usinghigher-order perception in a tactile sense.

By such a program according to the present technology, theabove-described decoding apparatus according to the present technologyis implemented.

Effects of the Invention

According to the present technology, a tactile reproduction system canbe made more efficient by achieving a data amount reduction of a tactilesignal while ensuring reproducibility of a tactile sense.

Note that the effect described here is not necessarily limited, and maybe any effect described in the present disclosure.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a diagram illustrating a configuration example of a tactilereproduction system including a decoding apparatus according to anembodiment of the present technology.

FIG. 2 is a diagram for describing an inner configuration example of anencoding apparatus according to an embodiment.

FIG. 3 is a diagram illustrating an inner configuration example of areproduction apparatus according to a first embodiment.

FIG. 4 is a diagram for describing an inner configuration example of adecoding apparatus according to an embodiment.

FIG. 5 is an explanatory diagram of a vibration detection thresholdcurve.

FIG. 6 is a diagram for describing an example of a finger contact typetactile device.

FIG. 7 is a diagram for describing an example of a body contact typetactile device.

FIG. 8 is an explanatory diagram illustrating phantom sensation.

FIG. 9 is an explanatory diagram illustrating an apparent movement.

FIG. 10 is an explanatory diagram illustrating an example of encodingthat uses phantom sensation.

FIG. 11 is a diagram illustrating an example of tactile stimulation tobe reproduced, as a diagram for describing an example of encoding thatuses an apparent movement.

FIG. 12 is a diagram exemplifying a relationship between a signaldetected by a sensor, and recorded data, as a diagram for describing anexample of encoding that uses an apparent movement.

FIG. 13 is a diagram for describing an example of an encoding formatthat uses higher-order perception.

FIG. 14 is a flowchart illustrating a procedure of specific processingfor implementing encoding according to an embodiment.

FIG. 15 is a diagram illustrating an example of block sizedetermination.

FIG. 16 is a functional block diagram for describing a function relatedto decoding that is included in a decoding apparatus according to anembodiment.

FIG. 17 is a flowchart illustrating a specific processing procedure tobe executed for implementing a decoding function according to anembodiment.

FIG. 18 is a diagram for describing a configuration example of anencoding apparatus according to a modified example of the firstembodiment.

FIG. 19 is a diagram illustrating a configuration example of a tactilereproduction system according to a second embodiment.

FIG. 20 is a diagram for describing an inner configuration example of areproduction apparatus according to the second embodiment.

FIG. 21 is a flowchart illustrating a specific processing procedure tobe executed for implementing an encoding method according to the secondembodiment.

FIG. 22 is a diagram illustrating an example of a higher-orderperception applied threshold value line.

FIG. 23 is a diagram illustrating an example of a GUI for adjusting ahigher-order perception applied threshold value.

MODE FOR CARRYING OUT THE INVENTION

Hereinafter, embodiments according to the present technology will bedescribed in the following order with reference to the attacheddrawings.

-   -   <1. First Embodiment>    -   [1-1. Overview of Tactile Reproduction System]    -   [1-2. Configuration of Encoding Apparatus]    -   [1-3. Configuration of Reproduction Apparatus]    -   [1-4. Configuration of Decoding Apparatus]    -   [1-5. Tactile Reproduction Method According to Embodiment]    -   (Encoding Method)    -   (Processing Procedure on Encoding Side)    -   (Functional Configuration and Processing Procedure on Decoding        Side)    -   [1-6. Modified Example of First Embodiment]    -   <2. Second Embodiment>    -   [2-1. Overview of Tactile Reproduction System]    -   [2-2. Configuration of Reproduction Apparatus]    -   [2-3. Encoding Method]    -   <3. Conclusion of Embodiment>    -   <4. Present Technology>

Here, in this specification, each term is defined as follows.

-   -   Tactile stimulation: physical phenomenon for causing a human to        perceive a tactile sense, such as a vibration phenomenon, for        example.    -   Tactile presentation: to generate tactile stimulation.    -   Tactile information: information perceived by a tactile sense,        such as vibration information, for example.    -   Tactile signal: signal indicating a pattern of tactile        stimulation, such as a signal indicating a vibration waveform,        for example.    -   Recipient: person who receives tactile presentation.    -   Tactile characteristic: characteristic regarding a tactile sense        of a human. Varies depending on the region (hand, face, foot and        the like).    -   Tactile sensitivity: sensitivity for subjectively determining        the intensity of tactile stimulation. Varies depending on the        receptor or the region in a human body.    -   Coded data: data obtained by encoding a signal. A stream and a        frame serve as a more specific concept.    -   Tactile coded data: data obtained by encoding a tactile signal.

1. First Embodiment 1-1. Overview of Tactile Reproduction System

FIG. 1 illustrates a configuration example of a tactile reproductionsystem 1 including a decoding apparatus (decoding apparatus 3) accordingto an embodiment of the present technology.

First of all, in the present embodiment, an environment for implementingtactile reproduction is divided into a recording environment forencoding a tactile signal obtained by sensing targeted tactileinformation (tactile stimulation), and recording tactile coded data Dcobtained by the encoding, and a reproduction environment for reproducingthe tactile information on the basis of a tactile signal obtained bydecoding the tactile coded data Dc.

As illustrated in the drawing, the tactile reproduction system 1includes a plurality of tactile sensors 5 and an encoding apparatus 2 towhich these tactile sensors 5 are connected, in the recordingenvironment, and includes a reproduction apparatus 4 configured toacquire the tactile coded data Dc, the decoding apparatus 3 configuredto wirelessly communicate with the reproduction apparatus 4, and aplurality of tactile presentation apparatuses 6 connected with thedecoding apparatus 3, in the reproduction environment.

The tactile sensor 5 is a sensor that performs sensing of tactilestimulation. In this example, a vibration sensor such as a piezo pickupsensor or an acceleration sensor is used. The tactile sensor outputsvibration or a motion as a voltage change by being brought into contactwith a target object of sensing, that is to say, a human body in thisexample.

In this example, the tactile sensors 5 are connected to the encodingapparatus 2 in a wired manner, and the tactile sensors 5 are attached todifferent regions of a human body serving as a target object, and sensetactile stimulation generated in the respective regions.

The encoding apparatus 2 includes a computer device such as, forexample, a central processing unit (CPU) and a digital signal processor(DSP), performs encoding of a detection signal (tactile signal) outputby each of the tactile sensors 5, in compliance with a predetermineddata format, and records the tactile coded data Dc obtained by theencoding, on a storage device provided inside, for example.

The reproduction apparatus 4 includes a computer device such as a CPUand a DSP, and transmits the acquired tactile coded data Dc to thedecoding apparatus 3. For example, the tactile coded data Dc recorded inthe recording environment is acquired by the reproduction apparatus 4via a required network such as the Internet. Alternatively, the tactilecoded data Dc can also be recorded on a portable storage medium, and thetactile coded data Dc can be acquired by the reproduction apparatus 4via the storage medium.

The decoding apparatus 3 decodes the tactile coded data Dc received bythe reproduction apparatus 4, and drives each of the tactilepresentation apparatuses 6 on the basis of a tactile signal obtained bythe decoding.

The tactile presentation apparatus 6 is assumed to be a device thatgenerates tactile stimulation. In this example, a vibration device suchas a vibrator or an actuator is used.

In this example, the tactile presentation apparatuses 6 are attached todifferent regions in a human body of a recipient, and reproduce tactilestimulation sensed by the corresponding tactile sensors 5.

Here, in this example, each of the tactile presentation apparatuses 6 isconnected to the decoding apparatus 3 in a wired manner, and a portionin the drawing that is surrounded by a broken line, that is to say, thedecoding apparatus 3 and the tactile presentation apparatuses 6 areassumed to be a part attached to a recipient.

The tactile reproduction system 1 can also have a configuration in whichthe reproduction apparatus 4 and each of the tactile presentationapparatuses 6 are connected in a wired manner, by providing functions ofthe decoding apparatus 3 in the reproduction apparatus 4, but in thiscase, the recipient to which the tactile presentation apparatuses 6 areattached might feel bothersome. The bothersome feeling is expected toincrease as the number of regions to which tactile stimulation isapplied increases.

By the configuration of the tactile reproduction system 1 that isillustrated in FIG. 1 , it becomes possible to prevent the recipientfrom feeling bothersome as described above.

The tactile reproduction system 1 illustrated in FIG. 1 is formed as asystem that reproduces a tactile sense of each region that is perceivedby a person to which the tactile sensor 5 is attached, in a recipient,and as a system that can also handle a case where the person and therecipient are arranged remotely.

Note that, in the present embodiment, the number of tactile sensors 5and the number of tactile presentation apparatuses 6, that is to say,the number of regions of a human body from which tactile stimulation issensed and reproduced is at least three or more.

1-2. Configuration of Encoding Apparatus

FIG. 2 is a diagram for describing an inner configuration example of theencoding apparatus 2. Note that FIG. 2 illustrates the tactile sensors 5illustrated in FIG. 1 , together with the inner configuration example ofthe encoding apparatus 2.

As illustrated in the drawing, the encoding apparatus 2 includes aplurality of amplifiers 21, a plurality of A/D converters 22, apreprocessing unit 23, an encoding unit 24, a control unit 25, a storageunit 26, a communication unit 27, and a bus 28. The preprocessing unit23, the encoding unit 24, the control unit 25, the storage unit 26, andthe communication unit 27 are connected via the bus 28 and enabled toperform data communication with each other.

A detection signal from each of the tactile sensors 5 is input to acorresponding one of the amplifiers 21, adjusted to an appropriatedynamic range, and then, input to a corresponding one of the A/Dconverters 22, and subjected to analog/digital conversion (A/Dconversion).

Each A/D-converted detection signal (that is, a tactile signal of eachregion) is input to the preprocessing unit 23. In the preprocessing unit23, various types of digital signal processing such as noise removal andcalibration of a sensor characteristic of the tactile sensor 5 areperformed.

Each tactile signal having been subjected to signal processing performedby the preprocessing unit 23 is input to the encoding unit 24.

The encoding unit 24 includes a DSP, for example, and encodes each ofthe input tactile signals in compliance with a predetermined dataformat, and obtains the above-described tactile coded data Dc.

Note that encoding of tactile signals according to the presentembodiment will be described later.

The control unit 25 includes a microcomputer including a CPU, a readonly memory (ROM), a random access memory (RAM), and the like, forexample, and controls the entire encoding apparatus 2 by executingprocessing in accordance with a program stored in the ROM.

For example, the control unit 25 performs data communication with anexternal device via the communication unit 27.

The communication unit 27 is configured to be able to perform datacommunication with an external device via a network such as theInternet, and the control unit 25 is configured to be able to performdata communication with an external device connected to the network, viathe communication unit 27. In particular, the control unit 25 isconfigured to be able to transmit the tactile coded data Dc obtained bythe encoding unit 24, to an external device via the communication unit27.

The storage unit 26 comprehensively represents a storage device such asa hard disk drive (HDD) and a solid state drive (SSD), for example, andis used for various types of data storage in the encoding apparatus 2.For example, data necessary for control by the control unit 25 is storedinto the storage unit 26. Furthermore, on the basis of control of thecontrol unit 25, the tactile coded data Dc obtained by the encoding unit24 can also be stored into the storage unit 26.

1-3. Configuration of Reproduction Apparatus

FIG. 3 is a diagram illustrating an inner configuration example of thereproduction apparatus 4.

As illustrated in the drawing, the reproduction apparatus 4 includes acontrol unit 41, a communication unit 42, a media drive 43, a storageunit 44, and a wireless communication unit 45, and also includes a bus46 that connects these components in such a manner that datacommunication can be performed with each other.

The control unit 41 includes a microcomputer including, for example, aCPU, a ROM, a RAM, and the like, and controls the entire reproductionapparatus 4.

The communication unit 42 is configured to be able to perform datacommunication with an external device via a network such as theInternet. The control unit 41 is configured to be able to perform datacommunication with an external device connected to the network, via thecommunication unit 42. In particular, the control unit 41 is configuredto be able to cause the communication unit 42 to receive the tactilecoded data Dc from an external device such as a server device on thenetwork.

The media drive 43 is configured to detachably include a portablestorage medium, and has a configuration as a reader/writer unit enabledto perform data writing and reading with respect to the attached storagemedium. Examples of storage media supported by the media drive 43include a memory card (for example, portable flash memory), an opticaldisc storage medium, and the like.

By the media drive 43, the tactile coded data Dc recorded on theportable storage medium can be read out.

The storage unit 44 comprehensively represents a storage device such asan HDD and an SSD, for example, and is used for various types of datastorage in the reproduction apparatus 4. For example, data necessary forcontrol by the control unit 41 is stored into the storage unit 44.Furthermore, on the basis of control of the control unit 41, the tactilecoded data Dc read out by the media drive 43, and the tactile coded dataDc received by the communication unit 42 from an external device canalso be stored into the storage unit 44.

The wireless communication unit 45 performs near field communicationusing a predetermined communication method such as Bluetooth (registeredtrademark), for example.

Here, as a part of the above-described overall control, the control unit41 performs control for executing reception of the tactile coded data Dcby the communication unit 42 and readout of the tactile coded data Dc bythe media drive 43. Furthermore, the control unit 41 controls thewireless communication unit 45 to transmit the tactile coded data Dcobtained via the communication unit 42 or the media drive 43, to thedecoding apparatus 3.

1-4. Configuration of Decoding Apparatus

FIG. 4 is a diagram for describing an inner configuration example of thedecoding apparatus 3, and illustrates the tactile presentationapparatuses 6 together with the inner configuration example of thedecoding apparatus 3.

As illustrated in the drawing, the decoding apparatus 3 includes aplurality of amplifiers 31, a plurality of D/A converters 32, apostprocessing unit 33, and a decoding unit 34, and also includes acontrol unit 35, a wireless communication unit 36, a storage unit 37,and a bus 38. The postprocessing unit 33, the decoding unit 34, thecontrol unit 35, the wireless communication unit 36, and the storageunit 37 are connected via the bus 38 and enabled to perform datacommunication with each other.

The control unit 35 includes a microcomputer including, for example, aCPU, a ROM, a RAM, and the like, and controls the entire decodingapparatus 3.

The wireless communication unit 36 performs near field communicationusing a method that can perform communication with the wirelesscommunication unit 45 in the reproduction apparatus 3, such asBluetooth, for example. The tactile coded data Dc transmitted from thereproduction apparatus 3 is received by the wireless communication unit36.

The storage unit 37 is assumed to be a storage device similar to thestorage unit 26, the storage unit 44, and the like, for example, and isused for the storage of various types of data to be used by the controlunit 35 and the like.

The decoding unit 34 decodes the tactile coded data Dc input via thewireless communication unit 36, using a method to be described later,and obtains a tactile signal of each region. The tactile signal of eachregion that has been obtained by the decoding unit 34 is input to thepostprocessing unit 33.

The postprocessing unit 33 performs, as necessary, signal processingsuch as the calibration of the tactile presentation apparatuses 6 andpredetermined filter processing on the input tactile signal of eachregion.

Each tactile signal having passed through the postprocessing unit 33 isinput to the corresponding one D/A converter 32 and subjected todigital/analog conversion (D/A conversion), and then, adjusted to anappropriate dynamic range by the corresponding one amplifier 31, andoutput to the corresponding one tactile presentation apparatus 6.

Therefore, each of the tactile presentation apparatuses 6 is driven onthe basis of the tactile signal, and can apply tactile stimulation to besensed in a detection environment, to a recipient (that is, canreproduce tactile information).

Note that the above description has been given only of a tactile signal,but a configuration of recording a voice signal or a video signaltogether with a tactile signal, and providing sound or a video to arecipient together with tactile information can also be employed.

1-5. Tactile Reproduction Method According to Embodiment Encoding Method

Hereinafter, a tactile reproduction method according to a first exampleof the first embodiment will be described.

First of all, a tactile reproduction method according to an embodimentis a method focused on a tactile characteristic of a human.

As an indication of tactile sensitivity of a human, a vibrationdetection threshold curve illustrated in FIG. 5 has been reported. Notethat, in FIG. 5 , a horizontal axis indicates a frequency and a verticalaxis indicates the magnitude of tactile stimulation (vibration:displacement in this example).

The vibration detection threshold curve illustrated in FIG. 5 indicateswhether or not a human feels the vibration as a tactile sense, that is,indicates an example of tactile sensitivity investigated through anexperiment. A human cannot perceive vibration smaller than the curve asa tactile sense.

The vibration detection threshold curves illustrated in FIG. 5 indicatethat a human can feel vibration up to about 1 kHz as tactilestimulation. Furthermore, FIG. 5 does not illustrate values equal to orlarger than 1 kHz, but it has been known that, actually, a human canperceive vibration at the frequency of about several kHz as tactilestimulation although the sensitivity is not high.

In a conventional application of tactile reproduction, in most cases,vibration of about 200 Hz at the most is targeted. This is attributed tothe fact that the highest tactile sensitivity of a human is obtained atabout 200 Hz.

However, as described above, it has been revealed from various pastexperiments that a human can feel vibration up to 1 kHz as tactilestimulation, and there is no choice but to say that it is difficult forthe conventional application to reproduce a tactile sense having a highsense of reality.

For example, vibration caused when a cork of a bottle is pulled outactually includes a high frequency such as several kHz. If vibration upto several hundreds Hz of the vibration is reproduced, a tactile sensetotally different from an actual tactile sense is obtained.

In view of the foregoing, in the present embodiment, a sense of realityis further enhanced by widening a bandwidth of characteristics of atactile signal and the tactile presentation apparatus 6 to about 1 kHz.

Specifically, in the present embodiment, a method of obtaining a tactilesignal by sensing tactile information such as vibration that has beengenerated in reality, and performing tactile presentation in accordancewith the tactile signal is employed.

In recent years every piece of information is digitalized and used.Similarly, handling of digitalized tactile signals will be considered.

A digitalized data amount can be considered on the basis of a bit depthnecessary per unit time, that is, a bit rate. For example, in thevibration detection threshold curve illustrated in FIG. 5 , a regionthat can be felt by a human is at least 50 dB (−20 dB to 30 dB) or moreon the vertical axis and about 1000 Hz on the horizontal axis. In thisexample, in view of a distribution of tactile information actually feltby a human, signals in a range of +20 dB from the threshold curve aresensed.

According to this, in the targeted frequency band up to 1000 Hz, avibration range becomes 70 dB (−20 dB to 50 dB).

If the vibration range is set to 70 dB in this manner in the targetedfrequency band up to 1000 Hz, in a case where a tactile signal isdigitalized by linear pulse code modulation (LPCM), because an amplitudethat can be represented by one bit is 6 dB, nine bits are necessary asfor the vertical axis, and 2000 Hz (sample/sec) being a double samplingfrequency is necessary for reproducing up to 1000 Hz. Thus, a necessarybit rate BO is obtained by the following Formula [1].

B0=12 bit/sample×2000 sample/sec=24 kbit/sec  [1]

Because the value itself is extremely small as compared with a bitrate=700 kbps/ch of compact disc (CD) being a representative format of avoice signal, for example, if the tactile signal is additionallyincorporated into a certain system, a large problem seems to hardlyoccur.

However, as described above, it has been seen that a bandwidth oftactile signals that can be felt by a human extends up to several kHz.For example, in a case where tactile signals are reproduced up to 2000Hz, a bit rate becomes a double of 48 kbit/sec as compared with Formula[1].

Furthermore, unlike a visual sense (two eyes) and an auditory sense (twoears), tactile senses exist everywhere on the body surface of a human.Tactile senses exist at ten points in the fingertips of both hands, andif tactile signals of all of these points are to be handled, a bit ratefurther increases to 480 kbit/sec, which is a tenfold bit rate. If thenumber of points are increased by considering each joint of a finger anda palm, a bit rate dramatically increases.

Moreover, basically, a tactile signal is a one-dimensional signal, but aphysical phenomenon of vibration can be considered in three axes (x, y,z). If all of these are handled, a necessary bit rate further increasesto 1440 kbit/sec, which is a threefold bit rate, but this value is alarge value exceeding 1411 kbit/sec of audio CD.

In this manner, although a bit rate regarding one tactile signal is notso large, if a tactile sense that can be felt by a human is considered,an immense amount is required, and large load is surely applied onto asystem that handles tactile signals.

Here, because the tactile presentation apparatus 6 is brought intocontact with a human body, in a configuration in which the decodingapparatus 3 and the reproduction apparatus 4 are connected in a wiredmanner, a recipient feels bothersome, and wireless connection asillustrated in FIG. 1 is desired. If a conventional major wirelessmethod is considered to be used for implementing wireless communicationat this time, in a broadband wireless method such as Wi-Fi (registeredtrademark), for example, the capacity of a battery might become largedue to large consumed power, and downsizing of a unit including thetactile presentation apparatuses 6 and the decoding apparatus 3 isaffected. Furthermore, in Wi-Fi, because a processing time is requiredfor a procedure performed from when a signal transmission request isgenerated, to when the signal transmission request is actually received,large latency might occur.

In contrast to this, in the case of a near field communication methodsuch as Bluetooth, because a structure of transmitting and receiving asignal with lower power consumption and lower latency as compared withother wireless methods can be used, the near field communication methodis considered to be suitably used for the purpose of tactilereproduction. However, in these near field communication methods, aninformation transmission amount is restricted, and when a voice signaland a tactile signal are considered to be transmitted and receivedsynchronously, for example, it can be said that an amount of dataallocated to a tactile signal is small.

Furthermore, a service that streams a video and voice via the Internethas become common, and in a case where adding tactile information forfurther enhancing a realistic feeling is considered, because acommunication speed of a line is already insufficient in the currentsituation, it can be said that an amount of data allocated to tactileinformation when a data amount is adjusted by a Quality of Service (QoS)function is small.

In view of the above-described circumstances, encoding a tactile signalhighly efficiently and transmitting the encoded tactile signal isconsidered. For example, in a case where a vibration signal is treatedas a tactile signal, a voice encoding method for a voice signal that isa one-dimensional signal similarly to a vibration signal, such as MPEGAudio Layer3 (MP3) or Advanced Audio Coding (AAC), for example, is alsoconsidered to be directly applied to a vibration signal, but the voiceencoding method is originally an encoding method that considers auralcharacteristics of a human, and does not consider characteristics of atactile sense. Thus, even if the voice encoding method is applied to avibration signal, information important for a tactile sense is highlylikely to be damaged, and the voice encoding method cannot implementoptimum encoding.

In view of the foregoing, the present embodiment aims to make a tactilereproduction system more efficient, by achieving a data amount reductionof a tactile signal while ensuring reproducibility of a tactile sense.

First of all, a specific example of a tactile device assumed in thepresent embodiment will be described with reference to FIGS. 6 and 7 .

FIG. 6 is a diagram for describing an example of a finger contact typetactile device. Specifically, FIG. 6 schematically illustrates acorrespondence relationship between fingers and tactile sensors 5 usedfor presenting tactile information to the fingers of a hand.

In this case, five tactile sensors 5 each attached to a correspondingone of the fingers are provided as tactile sensors 5. Hereinafter, thetactile sensors 5 attached to the respective fingers are distinguishedfrom each other by adding “-a” to “-e” to the ends of reference numeralsin order from a thumb side.

Note that FIG. 6 exemplifies only the tactile sensors 5, but fivetactile presentation apparatus 6 (6-a to 6-e) to be attached to therespective fingers are similarly provided as the tactile presentationapparatuses 6.

In a case where such a finger contact type tactile device is used, inthe recording environment, for example, a feeling felt when a fingertiptouches an object, impact generated when a ball is hit with a bat, andthe like can be sensed, and tactile signals corresponding to fivechannels can be acquired by one hand and tactile signals correspondingto ten channels can be acquired by both hands. Then, on the basis of theacquired tactile signals, in the reproduction environment, a recipienthaving the tactile presentation apparatuses 6-a to 6-e attached to therespective fingers can be caused to feel a feeling felt when an objectis touched, impact generated when a ball is hit with a bat, and thelike.

Note that, as a tactile device for implementing such tactilereproduction, for example, a configuration independent for each fingerlike a fingerstall type, or an integrated configuration like a glovetype can also be employed.

FIG. 7 is a diagram for describing an example of a body contact typetactile device. Specifically, FIG. 7 schematically illustrates tactilesensors 5 used for presenting tactile information to regions from abreast to a belly, and a positional relationship between the tactilesensors 5.

In the example in this drawing, the tactile sensors 5 are arrangedseparately on three rows in a vertical direction on the front surfaceside (breast and belly side) of a body. On each row, the number of thetactile sensors 5 arranged in a horizontal direction is three, and ninetactile sensors 5 in total are arranged on the front surface side of thebody. As illustrated in the drawing, these nine tactile sensors 5 aredistinguished from each other by adding “-f” to “-n” to the ends of thereference numerals.

Note that FIG. 7 exemplifies only the tactile sensors 5, but ninetactile presentation apparatuses 6 (6-f to 6-n) having similarpositional relationship are also provided as the tactile presentationapparatuses 6.

In a case where such a body contact type tactile device is used, in therecording environment, for example, by sensing a feeling felt when abody touches an object, impact generated when a body is shot by a gun orcut by a sword, and the like, tactile signals corresponding to ninechannels can be acquired on the front surface, and tactile signalscorresponding to 18 channels n total including the tactile signalsacquired on the back surface can be acquired. Then, on the basis of theacquired tactile signals, in the reproduction environment, a recipienthaving the tactile presentation apparatuses 6-f to 6-n attached in apositional relationship respectively corresponding to the tactilesensors 5-f to 5-n in the recording environment can be caused to feel afeeling felt when a body touches an object, impact generated when a bodyis shot by a gun or cut by a sword, and the like.

Note that the body contact type tactile device is considered to beprovided on a shirt-type cloth as illustrated in the drawing, or ajacket-type cloth, for example.

Here, similarly to other feelings of a human, higher-order perception isreported also for a tactile sense. The higher-order perception is aphenomenon in which information regarding physical stimulation isintegrated by a brain, and connected with complicated perception, and inthe case of a tactile sense, “phantom sensation” (Alles, D. S.:Information Transmission by Phantom Sensations, IEEE Trans. Man-machineSystems, Vol. 11, pp. 85-91, 1970), and “Apparent Movement”(Bekesy, G.V.: Sensation on the Skin Similar to Directional Hearing, Beats andHarmonics of the Ear, Journal of the Acoustic Society of America, Vol.29, No. 4, pp. 489-501, 1957) are mainly reported.

FIG. 8 is an explanatory diagram illustrating phantom sensation.

FIG. 8A illustrates that, among three points A to C of a human body thatare separated from each other by a certain distance, tactile stimulationis simultaneously applied only to the points A and C at both ends.According to phantom sensation, as illustrated in FIG. 8B, also at thepoint B to which stimulation is not applied, stimulation is perceived asif stimulation was applied simultaneously with the points A and C. Inother words, the phantom sensation is a phenomenon in which astimulation image is perceived between a stimulation point and astimulation point. At this time, in a case where stimulation intensitiesof the stimulation points are different, the stimulation image isperceived with being biased toward the stimulation point with higherstimulation intensity.

FIG. 9 is an explanatory diagram illustrating an apparent movement.

FIG. 9A illustrates that, to four points A to D of a human body that areseparated from each other by a certain distance, instantaneous tactilestimulation is chronologically applied in the order from the points A toD. FIG. 9B illustrates stimulation perceived in accordance with thestimulation illustrated in FIG. 9A being applied.

An apparent movement means a phenomenon in which stimulation betweenstimulation points is interpolated by a discrete chronological movementof a stimulation point, and stimulation is perceived as if a stimulationpoint was moving.

Note that perceiving tactile stimulation using phantom sensation isknown as disclosed in Reference Document 1 described below, for example.

Reference Document 1: Japanese Patent Application Laid-Open No.2013-044706

In the present embodiment, efficient encoding of a tactile signal isimplemented using the above-described higher-order perception isimplemented.

First of all, an example of encoding that uses phantom sensation will bedescribed with reference to FIG. 10 . Here, an example in which a fingercontact type tactile device as illustrated in FIG. 6 is used as atactile device will be described.

Among fingers of a human, some fingers often exist at positions close toeach other to some extent, due to the positional relationship betweenthe fingers and the restraint condition of joints. Therefore, somefingers often simultaneously perceive certain tactile stimulation. Forexample, when a certain object is picked up by a hand, an operation ofsimultaneously touching the object and then grabbing the object with aplurality of fingertips is performed. When a bat or a handle is grasped,a plurality of fingertips simultaneously touches the bat or the handle.FIG. 10A illustrates tactile signals to be detected by the tactilesensors 5-a to 5-e illustrated in FIG. 6 when a ball is actually pickedup. From FIG. 10A, it can be seen that, when a ball is picked up, allthe fingers simultaneously perceive tactile stimulation with similarintensity.

If it is considered that tactile reproduction is performed using thetactile presentation apparatuses 6-a to 6-e for obtaining thisperception, all tactile signals corresponding to the respective channelsillustrated in FIG. 10A can be recorded as-is, but stimulation appliedto the fingers existing between fingers, such as tactile signalsdetected by the tactile sensors 5-b and 5-d, specifically, can beomitted as illustrated in FIG. 10B, by using the generation of phantomsensation. In other words, an amount of tactile information to berecorded can be reduced.

If a structure in which the number of usage channels is variable isemployed in digital encoding, this reduction can be implemented bytemporarily excluding channels of the tactile sensors 5-b and 5-d fromusage channels, and an information amount can be thereby temporarilyreduced to ⅗ (reduction by 40%). Furthermore, even if an encoding methodin which the number of usage channels is fixed is employed, by employinga method of allocating zero to symbols of signals in correspondingperiods of the tactile sensors 5-b and 5-d, a reduction in informationamount can be achieved. In other words, setting symbols to zero leads todrastically reducing an information entropy, and in a case where entropyencoding (variable-length coding) such as Huffman coding is employed, avery large information amount reduction effect can be obtained.Furthermore, because a reduction in the number of the tactilepresentation apparatus 6 to be driven is achieved in addition to aninformation amount reduction, power saving and durability enhancementcan also be achieved.

An example of encoding that uses an apparent movement will be describedwith reference to FIGS. 11 and 12 .

Here, as an example of encoding that uses an apparent movement, anexample of a case where a body contact type tactile device asillustrated in FIG. 7 is used will be described.

A body of a human is a region with a relatively broad area, and amovement or propagation of tactile stimulation is often perceived.Examples of actions for enhancing a realistic feeling include an actionof cutting a body by a sword, an action of an insect or the likecrawling, and the like. Here, a case where an action of cutting a bodyby a sword in an arrow direction in the drawing is performed asillustrated in FIG. 11 , specifically, a case where an action of cuttinga body in a direction from the upper part of the left breast toward aright belly part, and then cutting the body in a direction from theright belly part toward a left belly part is performed will be describedas an example.

FIG. 12A exemplifies signals to be detected by the tactile sensors 5-fto 5-n when such an action is performed. As illustrated in the drawing,in this case, it can be seen that tactile stimulation is generated inthe order of the tactile sensors 5-h, 5-j, 5-l, 5-m, and 5-n.

In such tactile stimulation generated in accordance with the movement ofa certain object, a consciousness is given to a feeling of the movement,rather than a difference in property (intensity or frequency) of thetactile signal.

As stimulation applied when the above-described sword is moving, alltactile signals corresponding to the respective channels illustrated inFIG. 12A can be recorded as-is, but by interpolating stimulation betweena start point and an end point of tactile stimulation using thegeneration of an apparent movement, tactile signals can be reduced whilereproducing similar stimulation.

That is, if a structure of using accompanying information of actual dataof a signal is employed in digital encoding, for example, as illustratedin FIG. 12B, while a tactile signal of the tactile sensor 5-h isrecorded, tactile signals of the tactile sensors 5-j, 5-l, 5-m, and 5-nare not recorded, and instead, information indicating an instruction toreproduce the same tactile signal as the tactile signal of the tactilesensor 5-h at the respective positions of the tactile sensors 5-j, 5-l,5-m, and 5-n at appropriate times is recorded as accompanyinginformation (“accompanying information” in the drawing). Therefore, areduction in information amount can be achieved while enablingreproduction of stimulation generated when a sword is moving.Specifically, in the above-described example, an information amount ofthe corresponding period can be reduced to about (⅕)+α (α corresponds toaccompanying information) (reduction by 80−α %).

Note that the above description has been given of an example in which,among channels of tactile signals that can use an apparent movement,only a tactile signal of a single channel is recorded, but tactilesignals of two or more channels can also be recorded. For example, inthe case of tactile stimulation generated when a body is cut by a swordas exemplified in FIG. 11 , due to a change in the orientation of thesword at the position of the tactile sensor 5-l, or the like, adifference in property is considered to be generated between stimulationgenerated at positions of the tactile sensors 5-h to 5-j, andstimulation generated at the position of the tactile sensor 5-l andsubsequent sensors, and in this case, not only the tactile signaldetected by the tactile sensor 5-h but also the tactile signal detectedby the tactile sensor 5-l is also considered to be recorded forfaithfully reproducing the difference in stimulation.

FIG. 13 is a diagram for describing an example of an encoding formatthat uses higher-order perception.

Here, a digital tactile signal is a signal obtained by sampling achronological voltage change acquired by the tactile sensors 5, at apredetermined sampling frequency, and a signal similar to an LPCM methodin a voice signal is assumed. In the encoding of this example, such adigital tactile signal is divided in a time direction into framessuitable for transmission, and a header (frame header) is added asadditional information for each of the frames.

Specifically, a data format as illustrated in FIG. 13 is considered. Asillustrated in the drawing, one frame is provided with a header regionfor storing information that serves as a frame header, and an actualdata region for storing actual data of a tactile signal.

In the frame header, regions for storing pieces of information regardinga sync, a usage channel ID, a sampling frequency, a quantization bitrate, a block size, an apparent movement used channel ID, and anapparent movement usage channel ID are defined in order from thebeginning.

The sync serves as an identifier indicating the beginning of a frame.The usage channel ID indicates an identifier of a channel to be used asa channel of a tactile signal, among the maximum number of channelssupported by a system.

The sampling frequency and the quantization bit rate respectivelyindicate a sampling frequency of a tactile signal and a quantization bitrate per sample.

The block size indicates a size (the number of samples) in the timedirection of the tactile signal to be stored in the frame. Here, a blockindicates a processing unit in the time direction of the tactile signal.In the present embodiment, a block size is allowed to be changed foreach frame. Note that a reason why a block size is made variable in thismanner will be described later.

The apparent movement used channel ID indicates an identifier of achannel (hereinafter, will also be described as “used channel”) of whicha tactile signal is used by other channels, among channels that can usean apparent movement, when an apparent movement is used. For example, inthe case of the example illustrated in FIG. 12B, information indicatinga channel corresponding to the tactile sensor 5-h is stored in theapparent movement used channel ID.

The apparent movement usage channel ID indicates an identifier of achannel (hereinafter, will also be described as “usage channel”) thatuses a tactile signal of another channel, among channels that can use anapparent movement, when an apparent movement is used. For example, inthe case of the example illustrated in FIG. 12B, information indicatingchannels of the tactile sensors 5-j, 5-l, 5-m, and 5-n that use thetactile signal of the tactile sensor 5-h is stored in the apparentmovement usage channel ID.

In the actual data region following the header region, a tactile signalof each channel having a predetermined block size is stored.

By the encoding of the present embodiment, stream data having aconfiguration in which frames each having the above-described datastructure are arranged in the time direction is obtained. Theabove-described tactile coded data Dc is recorded and transmitted insuch a configuration of stream data.

Note that, in the stream data, actual data of a tactile signal isactually stored in a state of being interleaved for each channel, whichis not illustrated in the drawing.

Processing Procedure on Encoding Side

Subsequently, a procedure of specific processing for implementingencoding of a tactile signal that uses the above-described higher-orderperception will be described with reference to a flowchart in FIG. 14 .

Note that the processing illustrated in FIG. 14 is executed by theencoding unit 24 illustrated in FIG. 2 . The processing illustrated inFIG. 14 is executed for each frame described with reference to FIG. 13 .

In FIG. 14 , in Step S101, the encoding unit 24 determines whether ornot there is a channel where a signal similar to a certain channel issimultaneously generated. Specifically, the encoding unit 24 performsanalysis of tactile signals of the respective channels that are inputvia the preprocessing unit 23, at a fixed analysis length, and analyzeswhether or not there are simultaneously generated similar waveforms.Whether or not similar waveforms are simultaneously generated isdetermined by determining whether or not a difference in signal risingtime falls within a fixed range. Here, similar waveforms refer towaveforms of signals that have similar time envelopes. In this example,whether or not time envelopes are similar is determined by obtaining atime envelope similarity degree by calculating correlation betweensignals to be compared, and determining whether or not the time envelopesimilarity degree is equal to or larger than a predetermined thresholdvalue. Note that the analysis of similarity between time envelopes maybe performed by frequency analysis such as fast Fourier transform (FFT).

In a case where it is determined in Step S101 that there is a channelwhere a signal similar to a certain channel is simultaneously generated,the encoding unit 24 advances the processing to Step S102, in which theencoding unit 24 determines whether or not there is a channel that canuse phantom sensation. Specifically, the encoding unit 24 determineswhether or not there are three or more channels where similar waveformsare determined to be simultaneously generated, and there are three ormore consecutive channels on the surface of arrangement positions of thetactile sensors 5, among these channels.

If there is a channel that can use phantom sensation, the encoding unit24 advances the processing to Step S103, in which the encoding unit 24determines a channel not to be used. Specifically, for example, theencoding unit 24 determines, as a channel not to be used, aneven-numbered channel among the above-described three or moreconsecutive channels.

As for the channel determined in Step S103 described above, as a channelnot to be used, the encoding unit 24 does not store a channel ID into aregion of a channel ID in a frame header in frame header additionprocessing in Step S107, which will be described later, and does notstore a tactile signal in the actual data region.

Therefore, in response to a case where phantom sensation can be used, aninformation amount of a tactile signal can be efficiently reduced.

Note that the above description has exemplified a method of temporarilyexcluding a channel that can omit tactile stimulation, from a usagechannel, as a reduction method of an information amount that usesphantom sensation, but by allocating zero to an encoding symbol of atactile signal of the channel, without excluding the channel from ausage channel, an information amount reduction can also be achievedusing entropy encoding.

In accordance with executing the processing in Step S103, the encodingunit 24 advances the processing to Step S106 to be described later.

Furthermore, in a case where it is determined in Step S101 that there isno channel where a signal similar to a certain channel is simultaneouslygenerated, or in a case where it is determined in Step S102 that thereis no channel that can use phantom sensation, the encoding unit 24advances the processing to Step S104.

In Step S104, the encoding unit 24 determines whether or not there is achannel where a signal similar to a certain channel is generated withina predetermined time difference and within a sensor separated distance.Here, the sensor separated distance means a separated distance of thetactile sensors 5 between targeted channels.

In Step S104, the encoding unit 24 performs analysis of tactile signalsof the respective channels at a fixed analysis length (for example, 2 to3 seconds or the like), and analyzes whether or not there are similarwaveforms generated with a time difference within a predetermined time.Whether or not similar waveforms are generated with a time differencewithin a predetermined time is determined by determining whether or nota difference in signal rising time falls within a fixed range.Furthermore, similar waveforms are determined by analysis similar to theanalysis in Step S101.

In Step S104, on the basis of the above-described analysis, the encodingunit 24 determines whether or not there is a set of channels wheresimilar waveforms are generated with a time difference within apredetermined time, and in a case where there is the set of channels,the encoding unit 24 determines whether or not a sensor separateddistance between the channels in the set falls within a predetermineddistance.

The encoding unit 24 performs the determination processing in Step S104by a method of identifying a channel for which a positive result isobtained by the above-described determination, as a “channel where asignal similar to a certain channel is generated within a predeterminedtime difference and within a sensor separated distance”.

By the above-described processing in Step S104, for example, whenconsecutive tactile stimulation of cutting a body by a sword asexemplified in FIG. 11 is generated, if a generation time length of thetactile stimulation falls within a fixed time length (for example, 2 to3 seconds), as “channels where a signal similar to a certain channel isgenerated within a predetermined time difference and within a sensorseparated distance”, a set of channels of the tactile sensors 5-h and5-j, a set of channels of the tactile sensors 5-j and 5-l, a set ofchannels of the tactile sensors 5-l and 5-m, and a set of channels ofthe tactile sensors 5-m and 5-n are identified.

In a case where it is determined in Step S104 that there is a channelwhere a signal similar to a certain channel is generated within apredetermined time difference and within a sensor separated distance,the encoding unit 24 advances the processing to Step S105, in which theencoding unit 24 performs determination processing of a used channel anda usage channel of an apparent movement.

In this example, a used channel related to an apparent movement is achannel with the earliest timing of tactile stimulation (channel of thetactile sensor 5-h in the example in FIGS. 11 and 12 ) among channelsdetermined to be able to use an apparent movement, from the analysis inStep S104 (that is, channels of the tactile sensors 5-h, 5-j, 5-l, 5-m,and 5-n in the example in FIGS. 11 and 12 ). In other words, the usedchannel is a channel with the earliest signal rising timing.

Furthermore, a usage channel related to an apparent movement is achannel that generates second or subsequent tactile stimulation, amongchannels determined to be able to use an apparent movement.

Here, frame header addition processing to be performed by the encodingunit 24 varies between a case where a frame to be processed is a framecorresponding to the earliest tactile stimulation timing (hereinafter,described as an “initial frame”) among frames in a period of consecutivetactile stimulation that are determined to be able to use an apparentmovement, and a case where a frame to be processed is a framecorresponding to a second or subsequent tactile stimulation timing(hereinafter, described as a “non-initial frame”).

Specifically, in a case where a frame to be processed is an initialframe, in the frame header addition processing in Step S107, theencoding unit 24 stores a value indicating the above-described channelwith the earliest tactile stimulation timing, as a used channel ID inthe frame header, and stores an invalid value (that is, a valueindicating that there is no applicable value: for example, 0) as a usagechannel ID.

On the other hand, in a case where a frame to be processed is anon-initial frame, in the frame header addition processing in Step S107,the encoding unit 24 stores an invalid value (for example, 0) as a usedchannel ID, and stores a value indicating a channel in which rising of atactile signal is detected within the period of the frame, amongchannels determined to be able to use an apparent movement, as a usagechannel ID.

Here, in a case where a frame to be processed is a non-initial frame, atactile signal of a usage channel needs not be stored into the actualdata region, and an information amount reduction can be achieved byemploying a method of excluding the usage channel from a usage channel,for example. Alternatively, an information amount reduction can also beachieved by using entropy encoding by allocating zero to an encodingsymbol of a tactile signal in a usage channel.

In a case where the encoding unit 24 executes the determinationprocessing in Step S105, or in a case where it is determined in StepS104 that there is no channel where a signal similar to a certainchannel is generated within a predetermined time difference and within asensor separated distance, the encoding unit 24 advances the processingto Step S106.

In Step S106, the encoding unit 24 performs block size determinationprocessing. On the basis of the result of the waveform analysis in StepS101 or S104, a block size is determined in such a manner that therising of a signal comes to the beginning of a frame. Specifically, whenphantom sensation is used, for example, a range indicated by adouble-headed arrow in un upper part of FIG. 15A is set as a block size.Furthermore, in the case of an apparent movement, for example, a rangeindicated by a double-headed arrow in un upper part of FIG. 15B is setas a block size.

Note that FIGS. 15A and 15B illustrate an example in which a period ofone tactile stimulation is fitted within one block, but a period of onetactile stimulation can also be fitted within a plurality of blocks in adivided manner.

In FIG. 14 , in accordance with executing the block size determinationin Step S106, the encoding unit 24 executes the frame header additionprocessing in Step S107. Note that, because the details of the frameheader addition processing to be executed when phantom sensation isused, and when an apparent movement is used have already been described,the redundant description will be omitted.

In accordance with executing the processing in Step S107, the encodingunit 24 ends the series or processes illustrated in FIG. 14 .

Functional Configuration and Processing Procedure on Decoding Side

Subsequently, decoding of a tactile signal encoded by theabove-described method will be described.

FIG. 16 is a functional block diagram for describing a function relatedto decoding that is included in the decoding apparatus 3.

As illustrated in the drawing, the decoding apparatus 3 includesfunctions as an acquisition processing unit F1 and a decoding processingunit F2.

The acquisition processing unit F1 acquires the tactile coded data Dcobtained by performing encoding of compressing an information amount, ona tactile signal using higher-order perception in a tactile sense. Inthis example, the function of the acquisition processing unit F1corresponds to a function of the wireless communication unit 36receiving the tactile coded data Dc from the reproduction apparatus 4side.

The decoding processing unit F2 decodes the tactile coded data Dcacquired by the acquisition processing unit F2. The function of theacquisition processing unit F2 is implemented by the decoding unit 34.

In this example, the acquisition processing unit F1 acquires the tactilecoded data Dc having been subjected to encoding of compressing aninformation amount using phantom sensation or an apparent movement.

In a case where phantom sensation is used, the acquisition processingunit F1 acquires the tactile coded data Dc including usage channeldesignation information (usage channel ID in this example) fordesignating a usage channel from among three or more channels of tactilesignals. Then, the decoding processing unit F2 outputs a tactile signalof a channel indicated by the usage channel designation information.

Therefore, in implementing a data amount reduction that uses phantomsensation, the decoding apparatus 3 needs not perform processing such asprocessing of determining whether or not phantom sensation is used, byanalyzing coded data, and is only required to perform simple processingof outputting a tactile signal in accordance with usage channeldesignation information included in tactile coded data.

Furthermore, in a case where an apparent movement is used, theacquisition processing unit F1 acquires the tactile coded data Dcincluding usage presence/absence information indicating usagepresence/absence of an apparent movement, and the decoding processingunit F2 decodes the tactile coded data Dc on the basis of the usagepresence/absence information. In this example, information regarding anapparent movement used channel ID and an apparent movement usage channelID in a frame header correspond to the usage presence/absenceinformation.

As described above, in an initial frame among frames in a period ofconsecutive tactile stimulation that are determined to be able to use anapparent movement, because a valid value is stored as the apparentmovement used channel ID and an invalid value is stored as the apparentmovement usage channel ID, on the basis of the information regarding theapparent movement used channel ID and the apparent movement usagechannel ID, the decoding processing unit F2 can identify that a channelserving as a used channel exists in the frame, and can identify achannel ID of a used channel.

Furthermore, in a frame corresponding to a second or subsequent tactilestimulation timing, among frames in a period of consecutive tactilestimulation that are determined to be able to use an apparent movement,because an invalid value is stored as the apparent movement used channelID and a valid value is stored as the apparent movement usage channelID, on the basis of the information regarding the apparent movement usedchannel ID and the apparent movement usage channel ID, the decodingprocessing unit F2 can identify that a channel that is to use a waveformportion of a used channel in the initial frame exists in the frame, andcan identify a channel ID of a channel of which the waveform portion isto be used (to be output).

Furthermore, in a case where an apparent movement is used, theacquisition processing unit F1 acquires the tactile coded data Dcincluding a tactile signal of only a single channel among usablechannels of an apparent movement, and output control informationindicating an output channel and an output timing of the tactile signal,and the decoding processing unit F2 outputs the tactile signal of thesingle channel in accordance with the output control information.

In this example, information regarding an apparent movement used channelID and an apparent movement usage channel ID in a frame headercorrespond to the output control information. Information regarding theapparent movement usage channel ID functions as information indicatingan output channel and an output timing of a tactile signal in anapparent movement used channel of an initial frame, by a valid valuebeing stored in an appropriate frame.

A specific processing procedure to be executed for implementing theabove-described decoding function according to an embodiment will bedescribed with reference to a flowchart in FIG. 17 .

Note that the processing illustrated in FIG. 17 is executed by thedecoding unit 34 for each frame of the tactile coded data Dc.

First of all, in Step S201, the decoding unit 34 executes the frameheader analysis processing, and in following Step S202, the decodingunit determines whether or not an apparent movement is used.Specifically, the decoding unit 34 determines whether or not a validvalue is stored in at least either of the apparent movement used channelID and the apparent movement usage channel ID.

In a case where it is determined that a condition that a valid value isstored in at least either of the apparent movement used channel ID andthe apparent movement usage channel ID is not satisfied, and an apparentmovement is not used, the decoding unit 34 advances the processing toStep S205, in which the decoding unit 34 executes processing ofoutputting a tactile signal of a usage channel. Therefore, in responseto a case where a frame to be processed is a frame unrelated to the useof phantom sensation or an apparent movement, or a case where a frame tobe processed is a frame related to the use of phantom sensation, atactile signal of a usage channel indicated by a usage channel ID isoutput.

In accordance with executing the output processing in Step S205, thedecoding unit 34 advances the processing to Step S207 to be describedlater.

On the other hand, in a case where it is determined in Step S202 that anapparent movement is used, the decoding unit 34 advances the processingto Step S203, in which the decoding unit 34 determines whether or not acorresponding frame is an initial frame that uses an apparent movement.Specifically, the decoding unit 34 determines whether or not a validvalue is stored only in the former of the apparent movement used channelID and the apparent movement usage channel ID.

In a case where it is determined that a valid value is stored only inthe apparent movement used channel ID, and a corresponding frame is aninitial frame that uses an apparent movement, the decoding unit 34advances the processing to Step S204, in which the decoding unit 34executes processing of storing a tactile signal of a used channel, andthen, the decoding unit 34 advances the processing to Step S205.

Note that, by executing the processing in Step S205 after executing theprocessing in Step S204, in the initial frame, a tactile signal of aused channel is output.

Furthermore, in a case where it is determined in Step S203 that acondition that a valid value is stored only in the apparent movementused channel ID is not satisfied, and a corresponding frame is not aninitial frame that uses an apparent movement, the decoding unit 34advances the processing to Step S206. Note that a case where a negativeresult is obtained in Step S203 can be said to be a case where a validvalue is stored only in the apparent movement usage channel ID out ofthe apparent movement used channel ID and the apparent movement usagechannel ID.

In Step S206, the decoding unit 34 performs processing of outputting astored tactile signal of a used channel as a signal of a usage channel,and advances the processing to Step S207.

In Step S207, the decoding unit 34 determines whether or not decodingcorresponding to all channels has been completed. In a case where anegative result is obtained, the processing returns to Step S202, and ina case where a positive result is obtained, the series of processesillustrated in this drawing is ended.

By the above-described decoding processing, it is possible toappropriately decode the tactile coded data Dc having been subjected toencoding of compressing an information amount using higher-orderperception, and appropriately perform reproduction of tactileinformation sensed in the recording environment, using higher-orderperception.

1-6. Modified Example of First Embodiment

The above description has been given of an example of sensing a tactilesignal using the tactile sensor 5, but a tactile signal may be a signalobtained on the basis of a voice signal.

For example, a signal obtained by performing low-pass filter (LPF)processing on a voice signal with a sampling frequency of 48 kHz may beused.

FIG. 18 exemplifies a configuration on an encoding side in a case wherea tactile signal is obtained on the basis of a voice signal.

FIG. 18 exemplifies a configuration corresponding to a case where avoice signal is assumed to be a voice signal of 5.1 channel surround,for example. As illustrated in the drawing, an LPF 50 is prepared foreach channel of a voice signal, and tactile signals of the respectivechannels are obtained by extracting low-pass components (for example, 2kHz or less) from voice signals by these LPFs 50. An encoding unit 24Aobtains the tactile coded data Dc by performing encoding processingsimilar to the encoding unit 24, on the tactile signals of therespective channels that are obtained by these LPFs 50.

For example, in the case of content in which a stereotactic position ofa sound source can spatially move, such as surround content of 5.1channel, 7.1 channel, or the like, it is possible to reproduce a feelingof moving between different regions of a human body, such as a feelingof moving between fingers as a pseudo movement, or a feeling of movingfrom the breast to the belly as a pseudo movement.

In this case, the decoding apparatus 3 acquires the tactile coded dataDc obtained by the encoding unit 24A, and the decoding unit 34 performsdecoding processing similar to FIG. 17 on the acquired tactile codeddata Dc.

2. Second Embodiment 2-1. Overview of Tactile Reproduction System

Subsequently, a tactile reproduction system 1B of a second embodimentwill be described.

The second embodiment can make a criterion for determining whether ornot higher-order perception is used, variable in accordance with anindividual difference in sensitivity related to higher-order perception.

FIG. 19 is a diagram illustrating a configuration example of the tactilereproduction system 1B.

Note that, in the following description, parts similar toalready-described parts are assigned the same reference numerals, andthe description will be omitted.

The tactile reproduction system 1B includes a reproduction apparatus 4B,the decoding apparatus 3, a plurality of tactile presentationapparatuses 6 (at least three or more also in this example), and adisplay device 7.

The reproduction apparatus 4B is configured to acquire tactile data Dh.The tactile data Dh indicates a tactile signal of each channel that isconverted into digital data. In this example, the tactile data Dhindicates a tactile signal before being subjected to encoding accordingto an embodiment, that is, encoding of compressing an information amountusing higher-order perception.

The reproduction apparatus 4B is configured to perform encodingaccording to an embodiment on the tactile data Dh, and transmit thetactile coded data Dc obtained by the encoding, to the decodingapparatus 3 by wireless communication.

Furthermore, the display device 7 serving as a display device such as aliquid crystal display (LCD) or an organic electro-luminescence (EL)display, for example, is connected to the reproduction apparatus 4B, andthe reproduction apparatus 4B is configured to display various types ofinformation on the display device 7.

2-2. Configuration of Reproduction Apparatus

FIG. 20 is a diagram for describing an inner configuration example ofthe reproduction apparatus 4B, and illustrates the display device 7together with the inner configuration example of the reproductionapparatus 4B.

The reproduction apparatus 4B is different from the reproductionapparatus 4 illustrated in FIG. 3 in that a control unit 41B is providedin place of the control unit 41, and an encoding unit 24B, an operationunit 60, and a display control unit 61 are added.

The reproduction apparatus 4B can acquire the tactile data Dh via themedia drive 43 or by communication via the communication unit 42.

The encoding unit 24B inputs the tactile data Dh, that is to say, atactile signal of each channel, and obtains the tactile coded data Dc byperforming encoding processing according to an embodiment.

The encoding unit 24B is different from the encoding unit 24 in that theencoding unit 24B can change a criterion for determining whether or notto perform encoding that uses phantom sensation, and a criterion fordetermining whether or not to perform encoding that uses an apparentmovement.

As seen from the above description, in the embodiment, determination asto whether or not phantom sensation can be used is performed bydetermining whether or not a condition that a similarity degree of timeenvelope waveforms of tactile signals between channels to be compared isequal to or larger than a predetermined threshold value, and a conditionthat a difference between rising times of the tactile signals is equalto or smaller than a predetermined threshold value are satisfied.Furthermore, determination as to whether or not an apparent movement canbe used is also performed by determining whether or not a condition thata similarity degree of the time envelope waveforms between channels tobe compared is equal to or larger than a predetermined threshold value,and a condition that a difference between the rising times is equal toor smaller than a predetermined threshold value are satisfied.

The encoding unit 24B of this example is configured to change at least athreshold value of the above-described similarity degree of timeenvelope waveforms, and a threshold value of a difference between signalrising times, as a criterion for determining whether or not to performencoding that uses phantom sensation, and a criterion for determiningwhether or not to perform encoding that uses an apparent movement.

The operation unit 60 comprehensively represents various operationaltools provided in the reproduction apparatus 4B, and outputs operationinput information corresponding to an operation input, to the controlunit 41B.

The control unit 41B includes a microcomputer including, for example, aCPU, a ROM, a RAM, and the like, and controls the entire reproductionapparatus 4B by executing processing in accordance with a program storedin the above-described ROM or the like.

Note that processing according to an embodiment that is to be executedby the control unit 41B will be described below.

The display control unit 61 is connected to the bus 46, and performsdisplay control of the display device 7 on the basis of an instructionfrom the control unit 41B. The control unit 41B can thereby displayvarious types of information on the display device 7.

2-3. Encoding Method

In the second embodiment, a criterion for determining whether or not toperform encoding that uses phantom sensation or an apparent movement ischanged in such a manner that it becomes easier to perform the encodingthat uses phantom sensation or an apparent movement, as it is easier toperceive phantom sensation or an apparent movement.

Here, a criterion for determining whether or not to perform encodingthat uses phantom sensation or an apparent movement corresponds to athreshold value of the above-described similarity degree of timeenvelope waveforms and a threshold value of a difference between signalrising times. In the following description, these threshold values willbe collectively referred to as a “higher-order perception appliedthreshold value”.

Various methods can be considered as a method of defining a higher-orderperception applied threshold value in accordance with sensitivity of arecipient that is related to higher-order perception. Here, as anexample, the description will be given of a method of probativelyapplying tactile stimulation to a recipient, estimating a sensitivityrelated to higher-order perception in accordance with a response to thetactile stimulation from the recipient, and defining a higher-orderperception applied threshold value in accordance with the estimatedsensitivity.

FIG. 21 is a flowchart illustrating a specific processing procedure tobe executed for implementing an encoding method according to the secondembodiment.

Note that the processing illustrated in FIG. 21 is executed by thecontrol unit 41B in this example.

Here, the description will be given of processing corresponding to acase where the finger contact type tactile device illustrated in FIG. 6is used as a tactile device, and “a” to “e” in the drawing indicate therespective positions of the tactile device that are illustrated in FIG.6 .

First of all, in Steps S301 to S303, the control unit 41B executesprocessing for acquiring response information indicating levels ofstimulation respectively felt at the points b, c, and d when the pointsa and c, the points b and d, and the points c and e are simultaneouslystimulated.

The processing in Steps S301 to S303 is executed as processing ofissuing an instruction to simultaneously drive the tactile presentationapparatuses 6 at corresponding positions, to the decoding apparatus 3side via the wireless communication unit 45, displaying a receptionscreen of response information on the display device 7, and receiving anoperation input on the operation unit 60. At this time, a drive signalof the tactile presentation apparatus 6 is a pulse signal with fixedintensity.

The response information in this case is assumed to be informationregarding a score indicating a level of phantom sensation felt by therecipient in three stages (1: stimulation is not felt between stimulatedfingers/2: felt/3: strongly felt, etc.).

In Step S304 following Step S303, the control unit 41B executesprocessing for obtaining response information indicating a level of amovement feeling felt when the points a to e are sequentiallystimulated.

The processing is executed as processing of issuing an instruction tosequentially drive the tactile presentation apparatuses 6 atcorresponding positions, to the decoding apparatus 3 side via thewireless communication unit 45, displaying a reception screen ofresponse information on the display device 7, and receiving an operationinput on the operation unit 60.

The response information in this case is assumed to be informationregarding a score indicating a level of an apparent movement felt by therecipient in three stages (1: movement feeling is not felt/2: felt/3:strongly felt, etc.).

In Step S305 following Step S304, the control unit 41B calculates anaverage of the scores obtained in Steps S301 to 304 as responseinformation, and in Step S306, performs processing of obtaining ahigher-order perception applied threshold value that is based on thescore average value and a higher-order perception applied thresholdvalue line.

FIG. 22 illustrates an example of a higher-order perception appliedthreshold value line.

FIG. 22 exemplifies a higher-order perception applied threshold valueline corresponding to a case where a higher-order perception appliedthreshold value is a threshold value of the above-described similaritydegree of time envelope waveforms.

As illustrated in the drawing, the higher-order perception appliedthreshold value line in this case represents a smaller higher-orderperception applied threshold value as a score average value becomeshigher. In other words, the higher-order perception applied thresholdvalue line is designed in such a manner that a threshold value of thesimilarity degree of time envelope waveforms becomes lower as asensitivity related to higher-order perception becomes higher, and itbecomes easier to perform information compression that uses higher-orderperception, as a sensitivity related to higher-order perception becomeshigher. According to the higher-order perception applied threshold valueline exemplified in the drawing, 0.48 is obtained as a higher-orderperception applied threshold value when a score average value is 2.33.

Note that, in a case where a higher-order perception applied thresholdvalue is a threshold value of a difference between signal rising times,the higher-order perception applied threshold value line is onlyrequired to be inversely designed in such a manner that a higher-orderperception applied threshold value becomes smaller as the score averagevalue becomes higher.

By performing the above-described processing, it becomes possible toefficiently reduce a data amount of a tactile signal in accordance witha sensitivity of a recipient that is related to higher-order perception.

Note that the above description has been given of an example of settinga common higher-order perception applied threshold value between phantomsensation and an apparent movement, but different threshold values maybe set for phantom sensation and an apparent movement as higher-orderperception applied threshold values.

Here, as recipients, users with different preferences are assumed toexist. For example, some users desire to prevent transfer interruptioneven if the quality of a tactile signal is deteriorated. In contrast,the other users place importance on the quality of a tactile signal evenif transfer interruption is caused to some extent. It is considered toprovide a structure of enabling the users to adjust a higher-orderperception applied threshold value by themselves.

FIG. 23 is a diagram illustrating an example of a graphical userinterface (GUI) for adjusting a higher-order perception appliedthreshold value. Specifically, FIG. 23 illustrates an example of animage displayed on a display screen 7 a of the display device 7 for theadjustment of a higher-order perception applied threshold value.

In FIG. 21 described above, a term “higher-order perception appliedthreshold value” is used. In FIG. 23 , an index indicating easiness ofapplication of encoding that uses higher-order perception is representedas an “applied threshold value” for each combination of targetedfingers. That is, while a sensitivity of a user that is related tohigher-order perception is preliminarily surveyed and a threshold valueis defined in FIG. 21 , in FIG. 23 , the user can define an appliedthreshold value in accordance with the preference of the user. In theexample in FIG. 23 , the GUI enables adjustment of an applied thresholdvalue for each of phantom sensation and an apparent movement.

By setting a low applied threshold value, the user can cause informationcompression that uses higher-order perception, to be performed morefrequently, and can achieve transfer interruption prevention and powersaving. In contrast, by setting a high applied threshold value, the usecan cause information compression that uses higher-order perception, tobe hardly performed, and prevent a decline in accuracy of tactilereproduction as far as possible.

Furthermore, the GUI in FIG. 23 enables adjustment of an appliedthreshold value for the respective combinations of fingers between thepoints a and c, between the points b and d, and between the points c ande, as for an applied threshold value of phantom sensation. Therefore,for example, a user who recognizes that a feeling of an index finger iskeen but feelings of the other fingers are not so keen can preventimpairment of tactile information of a keen index finger, and achieve areduction in a data amount by compressing information regarding theother fingers, by setting a high phantom sensation applied thresholdvalue between the points a and c, and setting low applied thresholdvalues for the other combinations.

3. Conclusion of Embodiment

As described above, a decoding apparatus (decoding apparatus 3)according to an embodiment includes a decoding unit (the decodingprocessing unit F2, the decoding unit 34) that decodes tactile codeddata obtained by performing encoding of compressing an informationamount, on a tactile signal using higher-order perception in a tactilesense.

Therefore, a data amount reduction of a tactile signal can be performedin accordance with a tactile characteristic of a human.

Thus, a tactile reproduction system can be made more efficient byachieving a data amount reduction of a tactile signal while ensuringreproducibility of a tactile sense.

Furthermore, if higher-order perception is used, because output of atactile signal can be made unnecessary as for a channel (region) ofwhich a tactile signal is originally to be output, a reduction in thenumber of tactile presentation apparatuses to be driven is achieved, andpower saving and durability enhancement of tactile presentationapparatuses can be achieved.

Furthermore, in the decoding apparatus according to an embodiment, thedecoding unit decodes tactile coded data having been subjected toencoding of compressing an information amount using phantom sensation.

Therefore, in response to a case where similar tactile stimulation is tobe simultaneously applied to three or more regions of a human body, adata amount reduction can be performed in accordance with a tactilecharacteristic of a human.

Thus, a tactile reproduction system can be made more efficient byachieving a data amount reduction of a tactile signal while ensuringreproducibility of a tactile sense.

Moreover, in the decoding apparatus according to an embodiment, thetactile coded data includes usage channel designation information fordesignating a usage channel from among three or more channels of tactilesignals, and the decoding unit outputs a tactile signal of a channelindicated by the usage channel designation information.

Therefore, in implementing a data amount reduction that uses phantomsensation, the decoding apparatus needs not perform processing such asprocessing of determining whether or not phantom sensation is used, byanalyzing a tactile signal, and is only required to perform simpleprocessing of outputting a tactile signal in accordance with usagechannel designation information included in tactile coded data.

Thus, in enhancing efficiency of a tactile reproduction system, areduction in processing burden on the decoding apparatus and costreduction attributed to simplification of a configuration can beachieved.

Moreover, furthermore, in the decoding apparatus according to anembodiment, the decoding unit decodes tactile coded data having beensubjected to encoding of compressing an information amount using anapparent movement.

Therefore, in response to a case where similar tactile stimulation is tobe sequentially applied to different regions of a human body, a dataamount reduction can be performed in accordance with a tactilecharacteristic of a human.

Thus, a tactile reproduction system can be made more efficient byachieving a data amount reduction of a tactile signal while ensuringreproducibility of a tactile sense.

Furthermore, in the decoding apparatus according to an embodiment, thetactile coded data includes usage presence/absence informationindicating usage presence/absence of an apparent movement, and thedecoding unit decodes the tactile coded data on the basis of the usagepresence/absence information.

Therefore, in implementing a data amount reduction that uses an apparentmovement, the decoding apparatus needs not perform processing such asprocessing of determining whether or not an apparent movement is used,by analyzing a tactile signal, and is only required to perform simpleprocessing of outputting a tactile signal in accordance with usagepresence/absence information included in tactile coded data.

Thus, in enhancing efficiency of a tactile reproduction system, areduction in processing burden on the decoding apparatus and costreduction attributed to simplification of a configuration can beachieved.

Moreover, in the decoding apparatus according to an embodiment, thetactile coded data includes a tactile signal of only a single channelamong usable channels being channels of tactile signals that can use anapparent movement, and output control information indicating an outputchannel and an output timing of the tactile signal, and the decodingunit outputs the tactile signal of the single channel in accordance withthe output control information.

Therefore, in implementing tactile reproduction that uses an apparentmovement, tactile coded data needs not include a tactile signal of eachchannel to which tactile stimulation is to be applied, and it issufficient that a tactile signal of a single channel is included.

Thus, further reduction in a data amount of a tactile signal can beachieved, and a tactile reproduction system can be made furtherefficient.

Moreover, furthermore, in the decoding apparatus according to anembodiment, the single channel is a channel with the earliest signalrising timing among signals of the usable channels.

Therefore, in applying earliest tactile stimulation among sequentialtactile stimulation related to an apparent movement, it becomesunnecessary to stand by until a tactile signal indicating second orsubsequent tactile stimulation is acquired.

Thus, in implementing tactile reproduction that uses an apparentmovement, using only a tactile signal of a single channel, it ispossible to prevent latency from being unnecessarily generated.

Furthermore, in the decoding apparatus according to an embodiment, thedecoding unit decodes tactile coded data in which a size of a blockindicating a processing unit in the time direction is made variable.

Therefore, as for a tactile signal serving as a time signal, a specificwaveform portion and other portions can be treated as data includingdifferent blocks.

Thus, when only a specific waveform portion of a tactile signal isdesired to be targeted as in the case of using the above-describedphantom sensation or apparent movement, in the decoding apparatus, itbecomes unnecessary to perform processing of extracting the waveformportion from the tactile signal by signal analysis, and a reduction inprocessing burden related to decoding of a tactile signal encoded usinghigher-order perception can be achieved.

Moreover, in the decoding apparatus according to an embodiment, atactile signal is a signal that is based on a detection signal of atactile sensor.

Therefore, tactile reproduction can be performed on the basis ofactually-sensed tactile information.

Thus, reproducibility of a tactile sense can be enhanced.

Moreover, furthermore, in the decoding apparatus according to anembodiment, a tactile signal is a signal that is based on a voicesignal.

Therefore, tactile information having high association with voiceinformation can be reproduced.

Thus, tactile reproduction with a high entertainment property can beimplemented in tandem with a change in voice information by changing aregion to which tactile stimulation is applied, in accordance with achange in a stereotactic position of a sound source, for example.

Furthermore, a decoding method according to an embodiment is a decodingmethod of decoding tactile coded data obtained by performing encoding ofcompressing an information amount, on a tactile signal usinghigher-order perception in a tactile sense.

Also according to such a decoding method according to an embodiment,functions and effects that are similar to those of the above-describeddecoding apparatus according to an embodiment can be obtained.

Here, the functions of the encoding unit (24, 24A, 24B) and the decodingunit (34) that have been described so far can be implemented as softwareprocessing performed by a CPU and the like. The software processing isexecuted on the basis of a program, and the program is stored in astorage device from which programs can be read out by a computer device(information processing device) such as the CPU.

A program according to an embodiment is a program for causing aninformation processing device to implement a function of decodingtactile coded data obtained by performing encoding of compressing aninformation amount, on a tactile signal using higher-order perception ina tactile sense.

According to such a program, the above-described decoding apparatusaccording to an embodiment can be implemented.

Note that effects described in this specification are mereexemplifications and are not limited, and other effects may be caused.

4. Present Technology

Note that the present technology can also employ the followingconfigurations.

(1)

A decoding apparatus including:

-   -   a decoding unit configured to decode tactile coded data obtained        by performing encoding of compressing an information amount, on        a tactile signal using higher-order perception in a tactile        sense.        (2)

The decoding apparatus according to (1) described above,

-   -   in which the decoding unit decodes the tactile coded data having        been subjected to encoding of compressing an information amount        using phantom sensation.        (3)

The decoding apparatus according to (2) described above,

-   -   in which the tactile coded data includes usage channel        designation information for designating a usage channel from        among three or more channels of tactile signals, and    -   the decoding unit outputs a tactile signal of a channel        indicated by the usage channel designation information.        (4)

The decoding apparatus according to any of (1) to (3) described above,

-   -   in which the decoding unit decodes the tactile coded data having        been subjected to encoding of compressing an information amount        using an apparent movement.        (5)

The decoding apparatus according to (4) described above,

-   -   in which the tactile coded data includes usage presence/absence        information indicating usage presence/absence of an apparent        movement, and    -   the decoding unit decodes the tactile coded data on the basis of        the usage presence/absence information.        (6)

The decoding apparatus according to (5) described above,

-   -   in which the tactile coded data includes a tactile signal of        only a single channel among usable channels being channels of        tactile signals that can use an apparent movement, and output        control information indicating an output channel and an output        timing of the tactile signal, and    -   the decoding unit outputs the tactile signal of the single        channel in accordance with the output control information.        (7)

The decoding apparatus according to (6) described above,

-   -   in which the single channel is a channel with an earliest signal        rising timing among signals of the usable channels.        (8)

The decoding apparatus according to any of (1) to (7) described above,

-   -   in which the decoding unit decodes the tactile coded data in        which a size of a block indicating a processing unit in a time        direction is made variable.        (9)

The decoding apparatus according to any of (1) to (8) described above,

-   -   in which the tactile signal is a signal that is based on a        detection signal of a tactile sensor.        (10)

The decoding apparatus according to any of (1) to (8) described above,

-   -   in which the tactile signal is a signal that is based on a voice        signal.

REFERENCE SIGNS LIST

-   -   1, 1B Tactile reproduction system    -   2 Encoding apparatus    -   3 Decoding apparatus    -   4, 4B Reproduction apparatus    -   5 Tactile sensor    -   6 Tactile presentation apparatus    -   7 Display device    -   7 a Display screen    -   Dc Coded data    -   24, 24A, 24B Encoding unit    -   34 Decoding unit    -   36 Wireless communication unit    -   F1 Acquisition processing unit    -   F2 Decoding processing unit    -   50 LPF (low-pass filter)    -   Dh Tactile data    -   60 Operation unit

1. A decoding apparatus comprising: a decoding unit configured to decodetactile coded data obtained by performing encoding of compressing aninformation amount, on a tactile signal using higher-order perception ina tactile sense.
 2. The decoding apparatus according to claim 1, whereinthe decoding unit decodes the tactile coded data having been subjectedto encoding of compressing an information amount using phantomsensation.
 3. The decoding apparatus according to claim 2, wherein thetactile coded data includes usage channel designation information fordesignating a usage channel from among three or more channels of tactilesignals, and the decoding unit outputs a tactile signal of a channelindicated by the usage channel designation information.
 4. The decodingapparatus according to claim 1, wherein the decoding unit decodes thetactile coded data having been subjected to encoding of compressing aninformation amount using an apparent movement.
 5. The decoding apparatusaccording to claim 4, wherein the tactile coded data includes usagepresence/absence information indicating usage presence/absence of anapparent movement, and the decoding unit decodes the tactile coded dataon a basis of the usage presence/absence information.
 6. The decodingapparatus according to claim 5, wherein the tactile coded data includesa tactile signal of only a single channel among usable channels beingchannels of tactile signals that can use an apparent movement, andoutput control information indicating an output channel and an outputtiming of the tactile signal, and the decoding unit outputs the tactilesignal of the single channel in accordance with the output controlinformation.
 7. The decoding apparatus according to claim 6, wherein thesingle channel is a channel with an earliest signal rising timing amongsignals of the usable channels.
 8. The decoding apparatus according toclaim 1, wherein the decoding unit decodes the tactile coded data inwhich a size of a block indicating a processing unit in a time directionis made variable.
 9. The decoding apparatus according to claim 1,wherein the tactile signal is a signal that is based on a detectionsignal of a tactile sensor.
 10. The decoding apparatus according toclaim 1, wherein the tactile signal is a signal that is based on a voicesignal.
 11. A decoding method comprising: decoding tactile coded dataobtained by performing encoding of compressing an information amount, ona tactile signal using higher-order perception in a tactile sense.
 12. Aprogram for causing an information processing device to implement afunction of: decoding tactile coded data obtained by performing encodingof compressing an information amount, on a tactile signal usinghigher-order perception in a tactile sense.